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Search Results: 1 - 10 of 26204 matches for " Adelson Paulo;Teixeira "
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Relationships between grain yield and accumulation of biomass, nitrogen and phosphorus in common bean cultivars
Araújo, Adelson Paulo;Teixeira, Marcelo Grandi;
Revista Brasileira de Ciência do Solo , 2008, DOI: 10.1590/S0100-06832008000500019
Abstract: shoot biomass is considered a relevant component for crop yield, but relationships between biological productivity and grain yield in legume crops are usually difficult to establish. two field experiments were carried out to investigate the relationships between grain yield, biomass production and n and p accumulation at reproductive stages of common bean (phaseolus vulgaris) cultivars. nine and 18 cultivars were grown on 16 m2 plots in 1998 and 1999, respectively, with four replications. crop biomass was sampled at four growth stages (flowering r6, pod setting r7, beginning of pod filling r8, and mid-pod filling r8.5), grain yield was measured at maturity, and n and p concentrations were determined in plant tissues. in both years, bean cultivars differed in grain yield, in root mass at r6 and r7 stages, and in shoot mass at r6 and r8.5, whereas at r7 and r8 differences in shoot mass were significant in 1998 only. in both years, grain yield did not correlate with shoot mass at r6 and r7 and with root mass at r6. grain yield correlated with shoot mass at r8 in 1999 but not in 1998, with shoot mass at r8.5 and with root mass at r7 in both years. path coefficient analysis indicated that shoot mass at r8.5 had a direct effect on grain yield in both years, that root mass at r7 had a direct effect on grain yield in 1998, and that in 1999 the amounts of n and p in shoots at r8.5 had indirect effects on grain yield via shoot mass at r8.5. a combined analysis of both experiments revealed that biomass accumulation, n and p in shoots at r6 and r7 as well as root mass at r6 were similar in both years. in 1998 however bean accumulated more root mass at r7 and more biomass and n and p in shoots at r8 and r8.5, resulting in a 57 % higher grain yield in 1998. this indicates that grain yield of different common bean cultivars is not intrinsically associated with vegetative vigor at flowering and that mechanisms during pod filling can strongly influence the final crop yield. the esta
Variabilidade dos índices de colheita de nutrientes em genótipos de feijoeiro e sua rela??o com a produ??o de gr?os
Araújo, Adelson Paulo;Teixeira, Marcelo Grandi;
Revista Brasileira de Ciência do Solo , 2012, DOI: 10.1590/S0100-06832012000100015
Abstract: the use of genotypes with high biomass and nutrient accumulation but low nutrient harvest indices (ratio between nutrient amount in grains and in shoots) could reduce nutrient removal by harvesting and improve agricultural sustainability. the low variability found in the harvest indices in common bean (phaseolus vulgaris l.) calls for the evaluation of a wide range of genotypes. this study evaluated the variability of nutrient harvest indices and their relationship with grain yield in common bean genotypes. a field experiment was carried out in seropédica, state of rio de janeiro, with 64 bean genotypes (41 cultivars, 12 breeding lines and 10 landraces from the south of brazil) in four replications. the harvest indices were based on the amounts of biomass and nutrients accumulated in grains, stems and pod hulls after pod threshing. the average grain yield was 205 g m-2, with average harvest indices of biomass, n, p, k, ca, and mg of 0.62, 0.83, 0.89, 0.58, 0.33, and 0.51 g g-1, respectively, indicating an intense translocation of n and p to grains. the variability of these indices was relatively narrow. the residue dry mass after pod threshing was on average 107 g m-2, and contained 2.0, 0.15, 3.6, 2.8 and 1.3 g m-2 of n, p, k, ca and mg, respectively, wich suggests that these residues can meet a relatively great part of the crop nutrient demand. the phenotypic and genetic correlations (p < 0.001) were high, positive between grain yield and harvest indices of biomass and n, and negative between grain yield and n and p grain concentrations. since the phenotypic and genetic correlations between grain yield and p harvest index were less significant (p < 0.01), some genotypes with low p harvest index but good yields could be identified. the selection of common bean genotypes for improved grain yield can result in higher harvest indices of biomass and n, and also in larger nutrient amounts in grains and lower n and p grain concentrations.
Efeito do tamanho da semente na acumula??o de biomassa e nutrientes e na produtividade do feijoeiro
Perin, Adriano;Araújo, Adelson Paulo;Teixeira, Marcelo Grandi;
Pesquisa Agropecuária Brasileira , 2002, DOI: 10.1590/S0100-204X2002001200006
Abstract: this work intended to evaluate the effect of seed size on growth, nutrient accumulation and grain yield of common bean cultivars (phaseolus vulgaris l.) under field conditions. the experimental design was a randomized block in a 3x2 factorial arrangement with four replicates: three cultivars (kaboon, manteig?o and carioca) and two seed sizes (small and large). biomass was weekly sampled between 14 and 70 days after sowing. large seeds increased the plant height, the leaf area index and the shoot and root biomass since the first sampling but did not affect pod biomass. at the beginning of the experiment the large seeds increased the crop growth rate, but this effect disappeared at the end of sampling period. plants originating from large seeds accumulated more n and k in shoots and roots at 49 but not at 70 days after sowing. small seeds reduced the stand of cultivar carioca. there was no significant effect of seed size on grain yield, yield components and harvest index. large seeds can anticipate the growth of bean crop, but plants originating from small seeds may compensate their slower initial growth providing a similar grain yield.
Leaf senescence of common bean plants as affected by soil phosphorus supply
Araújo, Adelson Paulo;Kubota, Flavio Yuudi;Teixeira, Marcelo Grandi;
Revista Brasileira de Ciência do Solo , 2007, DOI: 10.1590/S0100-06832007000300010
Abstract: responses of leaf senescence to p supply could constitute adaptive mechanisms for plant growth under p-limiting conditions. the aim of this study was to evaluate the effects of soil p supply on leaf senescence of common bean (phaseolus vulgaris l.). eight p levels, ranging from 5 to 640 mg kg-1 p, were applied to pots containing four bean plants of cultivar carioca in 10 kg of an oxic haplustult soil. attached leaves were counted weekly, abscised leaves were collected every other day, and seeds were harvested at maturity. the number of live leaves increased until 48 days after emergence (dae) and decreased afterwards, irrespective of applied p levels. at lower applied p levels, the initial increase and the final decrease of leaf number was weak, whereas at higher applied p levels the leaf number increased intensively at the beginning of the growth cycle and decreased strongly after 48 dae. dry matter and p accumulated in senesced leaves increased as soil p levels increased until 61 dae, but differences between p treatments narrowed thereafter. the greatest amounts of dry mass and p deposited by senesced leaves were observed at 48-54 dae for high p levels, at 62-68 dae for intermediate p levels and at 69-76 dae for low p levels. these results indicate that soil p supply did not affect the stage of maximal leaf number and the beginning of leaf senescence of common bean plants, but the stage of greatest deposition of senesced leaves occurred earlier in the growth cycle as the soil p supply was raised.
Leaf area of common bean genotypes during early pod filling as related to plant adaptation to limited phosphorus supply
Trindade, Roberto Santos;Araújo, Adelson Paulo;Teixeira, Marcelo Grandi;
Revista Brasileira de Ciência do Solo , 2010, DOI: 10.1590/S0100-06832010000100012
Abstract: low phosphorus supply markedly limits leaf growth and genotypes able to maintain adequate leaf area at low p could adapt better to limited-p conditions. this work aimed to investigate the relationship between leaf area production of common bean (phaseolus vulgaris) genotypes during early pod filling and plant adaptation to limited p supply. twenty-four genotypes, comprised of the four growth habits in the species and two weedy accessions, were grown at two p level applied to the soil (20 and 80 mg kg-1) in 4 kg pots and harvested at two growth stages (pod setting and early pod filling). high p level markedly increased the leaf number and leaf size (leaf area per leaf), slightly increased specific leaf area but did not affect the net assimilation rate. at low p level most genotypic variation for plant dry mass was associated with leaf size, whereas at high p level this variation was associated primarily with the number of leaves and secondarily with leaf size, specific leaf area playing a minor role at both p level. determinate bush genotypes presented a smaller leaf area, fewer but larger leaves with higher specific leaf area and lower net assimilation rate. climbing genotypes showed numerous leaves, smaller and thicker leaves with a higher net assimilation rate. indeterminate bush and indeterminate prostrate genotypes presented the highest leaf area, achieved through intermediate leaf number, leaf size and specific leaf area. the latter groups were better adapted to limited p. it is concluded that improved growth at low p during early pod filling was associated with common bean genotypes able to maintain leaf expansion through leaves with greater individual leaf area.
Efeito do tamanho da semente na acumula o de biomassa e nutrientes e na produtividade do feijoeiro
Perin Adriano,Araújo Adelson Paulo,Teixeira Marcelo Grandi
Pesquisa Agropecuária Brasileira , 2002,
Abstract: O objetivo deste trabalho foi avaliar o efeito do tamanho da semente na acumula o de biomassa e nutrientes e no rendimento de gr os de cultivares de feijoeiro (Phaseolus vulgaris L.) no campo. O delineamento experimental foi em blocos ao acaso, em esquema fatorial 3x2 com quatro repeti es: três cultivares (Kaboon, Manteig o e Carioca) e dois tamanhos de semente (pequeno e grande). Foram efetuadas nove amostragens semanais de biomassa entre 14 e 70 dias após semeadura. As sementes grandes aumentaram a altura da planta, o índice de área foliar e a biomassa da parte aérea e raiz desde a primeira amostragem, mas n o modificaram a massa de vagens. No início do experimento, as sementes grandes aumentaram a taxa de crescimento da cultura, mas este efeito desapareceu ao final do período amostral. Plantas originadas de sementes grandes acumularam mais N e K na parte aérea e raízes aos 49 mas n o aos 70 dias após semeadura. Sementes pequenas reduziram o estande da cultivar Carioca. N o houve efeito do tamanho da semente na produ o de gr os, componentes de produ o e índice de colheita. Sementes de maior tamanho podem antecipar o crescimento do feijoeiro, mas plantas oriundas de sementes pequenas podem compensar seu menor crescimento inicial garantindo uma mesma produ o de gr os.
Effects of the size of sown seed on growth and yield of common bean cultivars of different seed sizes
Lima, Elvis Rodrigues;Santiago, Aline Silva;Araújo, Adelson Paulo;Teixeira, Marcelo Grandi;
Brazilian Journal of Plant Physiology , 2005, DOI: 10.1590/S1677-04202005000300001
Abstract: a field experiment was conducted to evaluate the effects of planting different sizes of seed of the same cultivar on biomass accumulation and grain yield of common bean (phaseolus vulgaris l.) cultivars of different seed sizes. a 6 x 2 split-plot factorial design with four replicates was employed, with six bean cultivars as main plots and two seed sizes (small and large, the latter twice as heavy as the former) of the same cultivar as subplots. eight weekly samplings of biomass were performed, and yield components were measured at maturity. large seeds increased the leaf area index and the shoot and root biomass of bean cultivars, particularly at the beginning of the growth cycle, but they did not affect the pod biomass. improved growth associated with the large seed was more intense for erect than for prostrate cultivars. plants originating from small seed presented a higher relative growth rate and net assimilation rate than plants from large seed. large seed did not affect grain yield, but reduced the number of seeds per pod, increased the 100-seed mass, and reduced the harvest index. the results indicate that sowing larger seeds of a bean cultivar can improve early-season plant growth, which might be advantageous for crop establishment in stress environments. however, some compensatory effect, associated with delayed leaf senescence, higher net assimilation rate, or greater number of seeds per pod, allows plants originating from small seed to achieve similar grain yield. lack of consistent effects of the seed size on grain yield indicate that the extra costs of sowing only the largest seed would not be profitable, but large seed resulted in larger grains at harvest which usually attain better market price.
Growth and yield of common bean cultivars at two soil phosphorus levels under biological nitrogen fixation
Pesquisa Agropecuária Brasileira , 2000, DOI: 10.1590/S0100-204X2000000400019
Abstract: the genotypic differences on growth and yield of common bean (phaseolus vulgaris l.) in response to p supply were evaluated in a field experiment under biological n2 fixation. eight cultivars were grown at two levels of applied p (12 and 50 kg ha-1 of p ? p1 and p2 respectively), in randomized block design in factorial arrangement. vegetative biomass was sampled at three ontogenetic stages. the effects of genotype and phosphorus were significant for most traits, but not the genotype ′ phosphorus interaction. the cultivars presented different patterns of biomass production and nutrient accumulation, particularly on root system. at p1, p accumulation persisted after the beginning of pod filling, and p translocation from roots to shoots was lower. the nodule senescence observed after flowering might have reduced n2 fixation during pod filling. the responses of vegetative growth to the higher p supply did not reflect with the same magnitude on yield, which increased only 6% at p2; hence the harvest index was lower at p2. the cultivars with highest yields also presented lower grain p concentrations. a sub-optimal supply of n could have limited the expression of the yield potential of cultivars, reducing the genotypic variability of responses to p levels.
Seeds enriched with phosphorus and molybdenum improve the contribution of biological nitrogen fixation to common bean as estimated by 15n isotope dilution
Chagas, Eduardo;Araújo, Adelson Paulo;Alves, Bruno José Rodrigues;Teixeira, Marcelo Grandi;
Revista Brasileira de Ciência do Solo , 2010, DOI: 10.1590/S0100-06832010000400009
Abstract: seeds with a high concentration of p or mo can improve the growth and n accumulation of the common bean (phaseolus vulgaris l.), but the effect of enriched seeds on biological n2 fixation has not been established yet. this study aimed to evaluate the effect of seeds enriched with p and mo on growth and biological n2 fixation of the common bean by the 15n isotope dilution technique. an experiment was carried out in pots in a 2 x 3 x 2 x 2 factorial design in randomized blocks with four replications, comprising two levels of soil applied p (0 and 80 mg kg-1), three n sources (without n, inoculated with rhizobia, and mineral n), two seed p concentrations (low and high), and two seed mo concentrations (low and high). non-nodulating bean and sorghum were used as non-fixing crops. the substrate was 5.0 kg of a red latosol (oxisol) previously enriched with 15n and mixed with 5.0 kg of sand. plants were harvested 41 days after emergence. seeds with high p concentration increased the growth and n in shoots, particularly in inoculated plants at lower applied p levels. inoculated plants raised from high p seeds showed improved nodulation at both soil p levels. higher soil p levels increased the percentage of n derived from the atmosphere (%ndfa) in bean leaves. inoculation with the selected strains increased the %ndfa. high seed p increased the %ndfa in inoculated plants at lower soil p levels. high seed mo increased the %ndfa at lower soil p levels in plants that did not receive inoculation or mineral n. it is concluded that high seed p concentration increases the growth, n accumulation and the contribution of the biological n2 fixation in the common bean, particularly in inoculated plants grown at lower soil p availability.
Decomposi??o e libera??o de nitrogênio, fósforo e potássio de resíduos da cultura do feijoeiro
Chagas, Eduardo;Araújo, Adelson Paulo;Teixeira, Marcelo Grandi;Guerra, José Guilherme Marinho;
Revista Brasileira de Ciência do Solo , 2007, DOI: 10.1590/S0100-06832007000400013
Abstract: the objective of this study was to measure the speed of decomposition and nutrient release in situ from residues of common bean (phaseolus vulgaris l.) crop. in field conditions, leaves of common bean cultivars senesced during the growth cycle and stems and podwalls after pod threshing were collected. these residues contained 2.3 mg ha-1 of mass, 31 kg ha-1 of n and 2.4 kg ha-1 of p that corresponded to 63, 41 and 28 % of total mass, n and p, respectively accumulated during the crop growth cycle. two experiments were conducted, during winter-spring and spring-summer. stems, podwalls and senesced leaves were placed separately in litterbags on the ground and collected, from the 2nd to the 120th day. the dry matter and nutrient amounts found in each residue type were adjusted to a simple exponential model. the half-life of the residues was, in the first and second trial respectively, 133 and 179 days for stems, 70 and 80 days for leaves, and 64 days for podwalls. the relatively slow residue decomposition may be associated with the high c:n ratio (c:n > 60 in stems and podwalls). nitrogen and p release by residues was similar to the decomposition pattern, while k release was faster. the results indicate that senescent leaves and residues produced after pod threshing can cover part of the nutrient demand of common bean crop, which is relevant for sustainable agricultural systems.
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